Grinding mill



March 10, 1942. M. L. RAHNER GRINDING MILL Filed Feb. 16, 1939 2 Sheets-Sheet l 'AHNER.

ATTORNEY.

INVENTOR M. I... RAHNER I 2 275 2 GRINDING MILL Filed Feb. 16, 1939 2 Sheets-Sheet 2 I INVENTOR.

MAXWELL LRAHNER.

YATTORNEY Patented Mar. 10, 1942 TED QFFICE '6 '.Claims.

This invention relates to grinding mills and more particularly to improved linings therefor, although certain features thereof may be employed with equal advantage forlother'purposes.

It contemrilatesmore especially the provision of improved liners for grinding mills effecting its function through motionand agitation of balls, tubes, rods, and similar devices with minimum wear upon the liners and the enclosing protective shell thereof.

Numerous types of grinding 'mill liners have heretofore been proposed and for the most part these are formed from cast-material or specially rolled plates having anchoring expedients connected to interposed lifting members. Specially rolled plates are expensive and it is not'entirely desirable to secure such in position through the lifting elements. The use of standard lifting elements such as rails and of standard shapes of steel plates provides a less expensive and more efiicient grinding mill liner. This is especially true in that it is customary in this art to; provide renewable lining sections to replace worn parts thereof, and the adaption of standard'elements such as rails and steel plates substantially eliminates the initial and replacement cost.

Then, too, the provision of liner plates as 'a retaining expedient for the lifting elements disposed therebetween is, so far as presently known, an advantageous departure from known parts. This affords the replacement of worn lifting members by merely loosening the intermediary plates, and their replacement is effected with minimum expense and time requirements.

One object of the presentinventi'on is to simplify the construction and improve the operation of devices of the charactermentioned.

Another object of the present invention is to provide grinding mill liners of standard shapes of plates and intermediary lifting elements to minimize the initial and replacement cost thereof.

Still another object is to provide grinding mill liners and standard shapes of plates and intermediary lifting elements and having the former as a securing member for the latter.

A further object is to provide a grinding mill liner consisting of standard steel plates and rails serving as lifting elements therefor with the shell anchoring expedients connected to intermediate plates to retain the lifting elements in operative position.

A still further objectvis to provide improved flat or curved rectangular rolled steel plates that operatively cooperate with lifting members to serve as an anchoring expedient therefor.

Still a further object'is to provide animproved liner plates consisting of a combined sheet and lifting element that are complemental .to each other for peening engagement responsive to fasteners connected therebetween and somewhat offset from the center of the liner plates to accomplish effective peening interengagement.

Other objects and advantages will appear from the following description of an illustrative embodiment-of the present invention.

'In the drawings:

Figure 1 is a sectional view in elevation atalren through a grinding mill illustrating *liner plates and lifting elements embodying features-of the present invention.

Figure 2 is a perspective view of a linerplate of the type shown in Figure 1.

Figure 3 is an enlarged fragmentary sectional perspective view of the grinding mill shown in Figure 1.

Figure 4 is a fragmentary perspective view of a modified grinding liner consisting of integral plates and lifting elements w-ith the anchoring means disposed therebetween.

Figure 5 is a fragmentary perspective sectional View of a still further modified form of liner plates and intermediary lifting elements.

Figure-6 is a perspective view ofa somewhat curved rectangular liner-plate of the type shown in Figure -5.

Figure 7 is afragmentary perspective sectional view of the'modified lifting element shown in Figure 5.

Figure 8 is a fragmentary perspective sectional View of fiat rectangular'liner plates with a still further'modified'form of lifting elementdisposed therebetween.

Figure 9 is a fragmentary perspective sectional view of curved rectangular lining plates combined with modified lifting elements 'thatarein circumferential alignment therewith.

The structure selected for illustration Loomprises a substantially cylindrical shell it of a conventional grinding-mill. The shell ii), in this instance,.has its interiorlined with-a plurality of detachably associated fiat steel rectangular plates .1 l. The substantially flat rectangular plates ll extend .for any desired length and width,.and,merely comprise .a component part .of the sectional liner that extends longitudinally for the length of the grinding mill shell i0. To this end, substantially flat liner plates H extend longitudinally of each .otherso that their ends 'I2-|f3 .are "in adjacent contact (Figure-3) and the number depend upon the requirements of handling and the lengthofthe particular grinding mill shell If together with the most efficient unit size thereof.

A plurality of frusto-conical apertures M and I5, in this instance two, are provided along :a longitudinal median line of each plate I! toreceive. anchoring fasteners such as :threaded bolts l Shaving correspondingly shapedand sized heads IT. The frusto-conical heads ll of the threaded fasteners l6 are preferably provided with a correspondingly sized nib l 3 to cooperate with properly sized grooves 28 provided in the inclined surfaces of the apertures I l-l 5. In consequence thereof, the shanks of the fasteners l6 will not turn as their nuts 2| are turned down tight against the shell ID with the fastener shank l6 projecting through suitable apertures 22 therein.

The width of the plates and the number thereof that are circumferentially spaced around the internal periphery of the shell depends upon the diameter thereof and the size of the lifting elements 23 disposed therebetween. The lifting elements 23 preferably though not essentially consist of standard rails having side channels 24 and 25 that define the rail head 26 and a substantially wider base flange 21, a cross section thereof being of standard and conventional design with the channels 24-45 serving to receive the side edges 28 and 29 of the liner plates disposed therebetween to define a continuous liner comprising the plates H and the intermediary lifting elements 23.

Turning the nuts 2| down tight exteriorly of the shell I!) will serve to retain the lifting elements 23 in a predetermined assemble-d relation therewith for turning with the shell l8. With this arrangement, the lifting elements 23 are secured indirectly by the liner plates H, and this affords the convenient replacement of either or both elements I |23 comprising the internal liner of the shell Hi. It should be observed that the lower longitudinal corners 30 and 3| of the liner plates II will engage the base 2! so as to effectively grip the steel therebetween to avoid the minutely ground materials confined interiorly of the liners ||23 to find their way to the shell I0, thereby avoiding appreciable wear and injury thereto over long periods of operating use.

It is to be noted that the lifting elements 23 such as the rails 25 can be composed of a single length or a plurality of lengths can be disposed in alignment so that their adjacent contacting edges 32 and 33 have joined contact to alternate with the adjacent engaging edges |2|3 of the liner plates (Figure 3). It will be apparent, therefore, that the inner liner plates II with their retaining elements 23 are composed of standard shapes now available on the market, and these structural elements provide an effective liner H with intermediary lifting elements 23 with comparatively small initial and replacement cost.

In the modified embodiment shown in Figure 4, the liner plates H are formed integral with the lifting members 23' to define a wave-like or sinusoidal liner configuration. The lifting elements 23 are alternately disposed to define complemental lifting element segments 24'25 presenting depending and upstanding flat inclined engaging surfaces 28' and 29. The bias or angle of the inclined surfaces 28'29 is sufficient to effect a peening action when engaged by the complemental lifting element segments 24'-25 of the next adjacent liner plate II to enable sealing engagement therebetween responsive to threaded fastener bolts |6' that extend therethrough for engagement by fastener nuts 2| in threaded engagement therewith on the exterior side of the shell I It is to be noted that the formation of the plate II' with its oppositely disposed complemental lifting element segments 24'-25', is such that the bottom surfaces 34 of the intermediary trough will be somewhat spaced from the inner surface of the shell l0 when the inclined contacting surfaces 28'-29' are in engagement. Consequently, when the fastener nuts 2| are drawn down tightly on the threaded shank I6, the trough surface 34 of the liner plates II will be outwardly displaced to contact the interior surface of the shell ID and effect a peening action between complemental lifting elements 23'. Then, too, the peening action can be rendered more effective by disposing the liner plate apertures |4'|5 slightly offset from the center longitudinal line thereof to rockably peen the lifting element 24' relative to the adjacent lifting element on the next liner plate I Consequently, an effective liner plate H and integral lifting elements 23' in the form of complemental segments 24'25' is provided to line the interior of the shell l0 without permitting any minute particles to find their way therebelow for undesirable packing against the interior surface of the shell I ll.

In a still further modified embodiment (Figures 5 to 7), the liner plates I" are substantially rectangular in configuration, and are curved transversely to conform with the curvature of the external shell H)". Then, too, the lifting elements 23" are specially constructed from the substantially rectangular plate 21", having a curvature corresponding with that of the external shell I U" and the liner plates for positioning therebetween. To this end, the lifting elements 23" have a convex head 26" of substantially greater curvature than its base plate 2'!" for confronting relation therewith, it being welded or otherwise joined thereto along the inter-engaging surface thereof as at 36 and 31 to present laterally extending flanges 38 and 39 to receive the liner plates thereon' The liner plates I" have their side edges 28" and 29" inclined outwardly and upwardly to substantially conform with the configuration of the convex lifting element head 26" in the region of its joinder to the base plate 2'!" thereof. Consequently, when the threaded fasteners I6" are projected through the correspondingly shaped apertures l4" and I5" in the liner plates H" and drawn tightly by the threaded fastener nuts 2|", the curved substantially curved liner plates II" will retain the lifting elements 23" in posi tion to define a continuous and effective liner having intermediate lifting elements to render the grinding action more effective.

In a still further modified embodiment (Figure 8), the substantially flat liner plates 40 are rectangular in configuration similar to those described in connection with Figures 1 to 3, but the lifting elements are constructed from substantially elongated and rectangular plates H welded or otherwise joined to lifting bars 42 to present laterally offset flanges 43 and 44 serving to receive the liner plates 40 thereon and therebetween. In the present embodiment, the bars 42 have fiat upper and lower surfaces with upwardly converging inclined sides 45 and 46 that project beyond the intermediate liner plates 40 having side edges 4'! and 48 inclined oppositely thereto to serve as a complement thereof.

Apertures 49 are provided in the liner plates 40 to receive threaded fasteners 50 havingcorrespondingly shaped heads 5| with non-turning nibs 52. The nibs 52 register with correspondingly inclined grooves 53 provided in the inclined wall of the liner plate apertures 49 to preclude relative rotation therebetween. Fastening nuts 54 engage the threaded fastening shank 50 with the shell 55 disposed therebetween. The fastener nuts 54 serve to draw the liner plates 40 in by engaging contact with the side lateral flanges 63- 14 of the lifting elements 42, thereby maintaining them in assembled relation to define a liner 40 combined with lifting elements 42 within the shell 55.

While the lifting elements 42 project upon the surface of the liner plates 40 in the embodiment which is described in Figure 8, in a still further modified embodiment shown in Figure 9, there is circumferential alignment between the upper surfaces of the lifting elements 42 and the arcuate surfaces of the liner plates 40' that are curved, in this instance, to correspond with the curvature of the shell 55'. It will be apparent, therefore, that the curved liner plates 40 together with the correspondingly sized lifting elements 42' define a continuous liner of smooth circumferential contour for anchored connection with the exterior shell 55 by means of the threaded fasteners described supra.

With. the arrangement of parts above described, it will be apparent that a very effective, simple, inexpensive and readily replaceable liner plates and lifting elements are provided to define the interior surface of a grinding mill possessing novel features of shape, structure, arrangement, and grinding shell action. Various changes may be made in the embodiment of the invention herein specifically described without departing from or sacrificing any of the advantages of the invention or any features thereof, and nothing herein shall be construed as limitations upon the invention, its concept or structural embodiment as to the whole or any part thereof except as defined in the appended claims.

I claim:

1. A grinding mill comprising a cylindrical shell, comparatively thin liner plates disposed along the interior circumference of said shell, comparatively narrow lifting elements associated with said liner plates which are mounted thereon to yield in the direction of said shell, said liner plates being many times wider than said lifting elements and normally spaced from the interior of said shell by said lifting elements, and shell anchored fastener means connected to said comparatively thin liner plates and shell intermediate said lifting elements for yielding said liner plates toward and attachment thereof and said lifting elements to said shell responsive to tightening said fastener means.

2. A grinding mill comprising a cylindrical shell, comparatively thin liner plates disposed along the interior circumference of said shell, comparatively narrow sectional lifting elements detachably associated with said liner plates which are mounted thereon to yield in the direction of said shell, said liner plates being substantially wider than said lifting elements and normally spaced from the interior of said shell by said lifting elements, said liner plates being effectually yieldable by being substantially wider than said lifting elements, and shell anchored fastener means connected to said comparatively thin liner plates and shell intermediate said lifting elements for yielding said liner plates toward and attachment thereof and said lifting elements to said shell responsive to tightening said fastener means.

3. A grinding mill comprising a cylindrical shell, comparatively thin rectangular liner plates disposed along the interior circumference of said shell, sectional lifting elements in the form of rails having side channels detachably associated with said liner plates, said liner plates being substantially wider than said lifting elements and normally spaced from the interior of said shell by said lifting elements by extending into the side channels thereof, and shell anchored fastener means connected to said comparatively thin liner plates and shell intermediate said lifting elements for yielding said liner plates toward and attachment thereof and said lifting elements to said shell responsive to tightening said fastener means.

4. A grinding mill comprising a cylindrical shell, comparatively thin flat rectangular liner plates disposed along the interior circumference of said shell, elongated rail form lifting elements having standard side channels detachably associated with said liner plates, said liner plates being substantially wider than said lifting elements and normally spaced from the interior of said shell by said lifting elements by extending into the side channels of said lifting elements, and shell anchored fastener means connected to said comparatively thin liner plates and shell intermediate said lifting elements for yielding said liner plates toward and attachment thereof and said lifting elements to said shell responsive to tightening said fastener means, said liner plates having sharp corner edge engagement with the side channels of said rails to preclude passage of the mill residue therethrough.

5. A grinding mill comprising a cylindrical shell, comparatively thin rectangular liner plates disposed along the interior circumference of said shell, lifting elements having inwardly protruding edges extending beyond said rectangular plates, said plates being substantially wider than said lifting elements and normally spaced from the interior of said shell, lateral flanges on said lifting elements for retaining engagement by said liner plates, said liner plates having sharp corner edge engagement with the side channels of said rails to preclude passage of the mill residue therethrough, and shell anchored fastener means connected to said liner plates and shell intermediate said lifting elements for yielding said liner plates toward and attachment thereof and said lifting elements to said shell responsive to tightening said fastener means.

6. A grinding mill comprising a cylindrical shell, comparatively thin rectangular liner plates disposed along the interior circumference of said shell, lifting elements having inwardly protruding edges extending in alignment with said rectangular plates, said plates being substantially wider than said lifting elements and normally spaced from the interior of said shell, lateral flanges on said lifting elements for retaining engagement by said liner plates, said liner plates having sharp corner edge engagement with the side channels of said rails to preclude passage of the mill residue therethrough, and shell anchored fastener means connected to said liner plates and shell intermediate said lifting elements for yielding said liner plates toward and attachment thereof and said lifting elements to said shell responsive to tightening said fastener means.

MAXWELL L. RAHNER. 

